Wait, /sit to trigger crits is p-server thing? I distinctly remember people saying that if you sit, you will be crit when I played 1.12 Vanilla. On top of that - there’s that pally that one shot Kazzak in early Vanilla because he stacked a shitload of reckoning when it didn’t have a limit - it’s not inconceivable that he did it without /sit to trigger crits, but it would take him so, SO long to do that without /sit.
For some weird reason Warlock used to be underrepresented in vanilla WoW. However, the least popular doesn’t mean that they were bad. Warlocks had amazing damage and some truly unique utility abilities allowing them to summon players or create Healthstones for the whole group. Similarly to Hunters, Warlocks were amazing for solo players with the ability to summon various demons to help them.
As you level, you will buy new ranks of spells. If you splurge out on an item upgrade, you will not have enough gold readily available to upgrade to the latest ranks of spells: placing you behind. Moreover, you can buy gear upgrades from the Auction House (AH) or vendors. Furthermore, you may have large investments that need to be paid for professors. You will need to purchase reagents and items such as leather, bolts of cloth, alchemy supplies – unless you have a charitable friend or another high-level alt.